The present invention is generally related to memory in the computer arts and, more particularly, is related to systems and methods for reducing the effect of noise while reading data in series from memory.
Magneto-resistive devices such as a magnetic random access memory (MRAM) device and a write-once memory device store data. The magneto-resistive devices include memory cells and each memory cell stores a data xe2x80x9c1xe2x80x9d or a data xe2x80x9c0xe2x80x9d. Each memory cell of the magneto-resistive device includes a soft layer that is located above or below a tunneling junction and a hard layer that is located opposite to the soft layer.
Typically, a high gain sense amplifier is used to read data from each memory cell of the magneto-resistive device. Unfortunately, the high gain sense amplifier is subject to noise while reading the data since the high gain sense amplifier is built from circuits that are subject to alternating current (AC) noise, power supply noise, coupled digital switching noise, and noise associated with small area of the magneto-resistive device.
Signal-to-noise ratio (SNR) of the high gain sense amplifier is optimized to offset the effect of the noise to which the high gain sense amplifier is subject. Optimization of the SNR generally results in increased costs or being unable to meet SNR specifications of the computer arts since noise-reduction techniques are used to optimize the SNR of the high gain sense amplifier. Examples of noise-reduction techniques include low noise design and physical layout techniques. Noise reduction techniques often result in increased costs because of increased complexity of a circuit executing one of the noise-reduction techniques, increased physical area occupied by the circuit, or increased cost of executing one of the noise-reduction techniques.
A need exists in the industry to overcome the above-mentioned inadequacies of increased costs or failure to meet the SNR specifications, or other inadequacies or deficiencies.
The present invention provides systems and methods for reducing the effect of noise while reading data in series from memory.
Briefly described, in architecture, one embodiment of the system can be implemented as follows: a memory cell that stores a first data; a sensing device that receives the first data multiple times and provides a first set of outputs; and a voting system that evaluates the first set of outputs to determine whether one of the outputs of the first set is valid data from the memory cell.
The present invention can also be viewed as providing methods for reducing the effect of noise while reading data from memory. In this regard, one embodiment of such a method, among others, can be broadly summarized by the following steps: reading data in series that is stored in a memory cell to provide outputs; and evaluating the outputs to determine whether one of the outputs is valid data from the memory cell.